Luminaires or lighting fixtures are used for providing artificial light where needed, such as in buildings or outdoor areas. A typical arrangement includes a plurality of light sources carried in a single, elongated fixture and arranged in tandem for lighting a particularly wide area, such as an open floor space in a warehouse or an office space. While this type of lighting generally performs without incident due in part to the utilization of adequate heat sinks, controlling the power supplied to the plurality of light sources dependent upon an ambient temperature can extend the useful life of the plurality of light sources. Taking measures to insure the proper functioning of the heat sinks can likewise extend the useful life of the plurality of light sources.
In a first instance, the useful life can be extended by limiting the possibility for heat related damage that can arise from exposure to an ambient temperature in a range sufficient to cause damage to the plurality of light sources.
In a second instance, the useful life of the plurality of light sources can be extended by reducing the power supplied to the plurality of light source when an ambient temperature is below a threshold ambient temperature while maintaining an output of the plurality of light sources at a substantially constant level.
In a third instance, the useful life of the plurality of light sources can be extended by monitoring ambient temperatures within the lighting fixture and at a second position apart from the fixture to insure proper functioning of the heat sinks. A significant difference between the monitored ambient temperatures could indicate that the heat sink requires maintenance or cleaning.
Accordingly, a need is identified for an improved luminaire that provides the ability to extend the useful life of the plurality of light sources by controlling the power supplied to the plurality of light sources dependent upon an ambient temperature. This may be accomplished by limiting the possibility for heat related damage and reducing the power supplied to the plurality of light sources for greater efficiency at lower ambient temperatures. The ability to control the power supplied to the plurality of lights sources is of heightened importance in enclosed spaces such as warehouses, factories, or other industrial establishments. Even more, the useful life may be extended by monitoring ambient temperatures to insure proper functioning of heat sinks associated with the luminaire. The luminaire would be simple in construction, and could be adjusted in a variety of manners in order to achieve the desired objectives of controlled lighting. Related improvements are also proposed.